Position and pressure master-slave control method of hydraulic servo system of valve-controlled cylinder

Abstract

The invention relates to a position and pressure master-slave control method of a hydraulic servo system of a valve-controlled cylinder, and belongs to the technical field of control of a high-flow quantity and high-speed hydraulic servo system. The method comprises the following steps of using a position signal in the hydraulic servo system of the valve-controlled cylinder as a master feedback signal of the whole system, and using the position control as the master closed loop control of the whole system; using a pressure signal as a slave control signal, and using the pressure feedback control as the slave closed loop control; and introducing the pressure conversion gain into the slave closed loop control, when the load of an executing mechanism reaches the setting range of the master control pressure, starting the position and pressure master-salve control of the hydraulic servo system of the valve-controlled cylinder, comparing the actual pressure signal with the given pressure signal to obtain a result, converting the result into a position deviation signal, compensating the deviation signal into a position closed loop of the whole system, and enabling the system to adjust a servo valve by a master-salve PID (proportional integral differential) controller according to the general position deviation signals, so as to precisely adjust the position of a hydraulic cylinder. The method has the advantages and beneficial effects that the position and pressure master-salve control of the hydraulic servo system is realized, the control precision of the system is improved, and the control performance of the system is improved.

Description

technical field [0001] The invention belongs to the technical field of large-flow, high-speed hydraulic servo system control, and in particular relates to a master-slave control method for the position and pressure of a valve-controlled cylinder hydraulic servo system. Background technique [0002] In the large flow, high speed valve-controlled cylinder hydraulic servo system, in many cases, it is necessary to realize the master-slave control of position and pressure, which requires the establishment of a hybrid control model. The position and pressure hybrid control model of the system is very complex, with nonlinearity and great uncertainty, and there are often some unknown disturbances in the working environment, so its control performance, such as stability, frequency response or load sensitivity, etc. will be reduced or worse. The position closed-loop and pressure closed-loop of the valve-controlled cylinder hydraulic servo system cannot be accurately controlled at the...

AI Technical Summary

Problems solved by technology

The position and pressure hybrid control model of the system is very complex, with nonlinearity and great uncertainty, and there are often some unknown disturbances in the working environment, so its control performance, such as stability, frequency response or load sensitivity, etc. will be reduced or become worse

The position closed-loop and pressure closed-loop of valve-controlled cylinder hydraulic servo system cannot be precisely controlled at the same time, which limits the further development of hybrid control of hydraulic servo system

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